Method of processing perovskite solar cell modules

Abstract

Provided is a method for treating a perovskite solar cell module capable of removing or recovering lead from a cleaning solvent of the perovskite solar cell module by a simple method; according to the present invention, a method for treating a perovskite solar cell module is provided, which includes a dissolving step, a precipitation step, and a solid-liquid separation step, in the dissolving step, a plurality of functional layers are peeled from a transparent substrate while a perovskite photoelectric conversion layer is dissolved in a cleaning solvent by immersing the perovskite solar cell module in the cleaning solvent and applying ultrasonic waves, in the precipitation step, lead dissolved in the cleaning solvent is precipitated as a hardly soluble lead compound, and in the solid-liquid separation step, the lead compound is separated from the cleaning solvent.

Description

Technical Field

[0001] This invention relates to a method for processing perovskite solar cell modules, used to process used or poorly manufactured perovskite solar cell modules that are destined for disposal. Background Technology

[0002] Patent document 1 discloses a technique for removing the functional layers of a perovskite solar cell module by immersing it in a specified cleaning solvent.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6997705 Summary of the Invention

[0006] Since perovskite solar cell modules typically contain lead, the cleaning solvents that dissolve the functional layers of these modules will also contain lead. As the use of perovskite solar cell modules increases in the future, it will be necessary to ensure that the cleaning solvents used in these modules meet emission standards. Therefore, a technology is desired that can remove or recover lead from the cleaning solvents of perovskite solar cell modules using a simple method.

[0007] The present invention was made in view of this situation and aims to provide a method for treating perovskite solar cell modules that can remove or recover lead from the cleaning solvent of the perovskite solar cell module by a simple method.

[0008] According to the present invention, the following invention is provided.

[0009] [1]: A method for processing a perovskite solar cell module, comprising a dissolution step, a precipitation step, and a solid-liquid separation step, wherein the perovskite solar cell module comprises a transparent substrate and multiple functional layers, wherein the multiple functional layers include a perovskite photoelectric conversion layer, wherein in the dissolution step, the perovskite solar cell module is immersed in a cleaning solvent and ultrasonic waves are applied to peel the multiple functional layers off the transparent substrate, and the perovskite photoelectric conversion layer is dissolved in the cleaning solvent, wherein in the precipitation step, lead dissolved in the cleaning solvent is precipitated as a sparingly soluble lead compound, and wherein in the solid-liquid separation step, the lead compound is separated from the cleaning solvent.

[0010] [2]: The perovskite solar cell module processing method as described in [1], wherein the cleaning solvent is a dilute sulfuric acid aqueous solution and the sparingly soluble lead compound is lead sulfate.

[0011] [3]: A method for processing perovskite solar cell modules as described in [1] or [2], wherein, in the dissolution step, the cleaning solvent is heated to 40-80°C.

[0012] [4]: A method for processing a perovskite solar cell module as described in any one of [1] to [3], wherein, in the precipitation step, the cleaning solvent is cooled to below 10°C.

[0013] [5]: A method for processing a perovskite solar cell module as described in any one of [1] to [4], wherein the method further includes an adsorption step, wherein lead remaining in the cleaning solvent after the solid-liquid separation step is adsorbed by a lead removal filter in the adsorption step.

[0014] [6]: A method for processing a perovskite solar cell module as described in any one of [1] to [5], wherein the lead content of the cleaning solvent after the solid-liquid separation step or the lead content of the cleaning solvent after the adsorption step is less than 0.05 mg / L.

[0015] (Invention effect)

[0016] The perovskite solar cell module processing method of this invention uses a simple approach involving dissolution, precipitation, and solid-liquid separation steps to separate lead from the cleaning solvent that has dissolved the photoelectric conversion layer. Therefore, the cleaning solvent can be discharged legally while meeting emission standards, and it can also handle increased volumes of cleaning solvent used. Furthermore, useful resources can be recovered from the lead-removed cleaning solvent and reused as needed. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating a processing method for a perovskite solar cell module 1 according to one embodiment.

[0018] Figure 2A This is a perspective view showing the schematic structure of the perovskite solar cell module 1. Figure 2B This is a diagram representing a general structure of multiple functional layers 3.

[0019] Figure 3A This is a schematic diagram of the dissolution step (S1). Figure 3B This is a diagram showing the state of the perovskite solar cell module 1 after the dissolution step (S1). Figure 3C This is an example diagram showing the state of the solvent 4 being stirred and cleaned by the stirrer 6 in the precipitation step (S2).

[0020] (Symbol Explanation)

[0021] 1: Perovskite solar cell module

[0022] 2: Transparent substrate

[0023] 3: Functional layer

[0024] 4: Cleaning solvent

[0025] 5: Ultrasonic vibrator

[0026] 6: Blender

[0027] 20: Temperature

[0028] 31: Transparent electrode layer

[0029] 32: Electron transport layer

[0030] 33: Perovskite photoelectric conversion layer

[0031] 34: Hole transport layer

[0032] 35: Back electrode layer

[0033] 36: Sealing layer

[0034] 37: Backsheet layer

[0035] 40: Container Detailed Implementation

[0036] The embodiments of the present invention will now be described. The various features shown in the embodiments described below can be combined with each other. Furthermore, each feature can also constitute an invention independently.

[0037] <An overview of processing methods for perovskite solar cell modules>

[0038] like Figure 1 As shown, the processing method for the perovskite solar cell module 1 in this embodiment includes a dissolution step (S1), a precipitation step (S2), and a solid-liquid separation step (S3). In this embodiment, the object being processed is a used perovskite solar cell module 1. However, in addition to used perovskite solar cell modules 1, modules that are discarded due to defects generated during the manufacturing process can also be processed by this invention.

[0039] like Figure 2A As shown, the perovskite solar cell module 1 includes a transparent substrate 2 and multiple functional layers 3. The transparent substrate 2 is, for example, a glass substrate. However, the present invention can also be well applied even if the transparent substrate 2 is a resin film.

[0040] Multiple functional layers 3 are formed on the transparent substrate 2. The multiple functional layers 3 are as follows: Figure 2BAs shown, the structure includes a transparent electrode layer 31, an electron transport layer 32, a perovskite photoelectric conversion layer 33, a hole transport layer 34, a back electrode layer 35, a sealing layer 36, and a backplate layer 37. The structures of each layer can be well-known, therefore descriptions are omitted. Furthermore, this invention is also well-suited for handling perovskite solar cell modules 1 with different configuration sequences of multiple functional layers 3 (e.g., structures with a glass substrate, transparent electrode layer, hole blocking layer, electron transport layer, perovskite photoelectric conversion layer, hole transport layer, and back electrode (Au) stacked layers, etc.).

[0041] In the dissolution step (S1), as Figure 3A As shown, by immersing the perovskite solar cell module 1 in a cleaning solvent 4 and applying ultrasonic waves, multiple functional layers 3 are peeled off from the transparent substrate 2, while the perovskite photoelectric conversion layer 33 dissolves in the cleaning solvent 4. In this embodiment, an ultrasonic vibrator 5 is provided on the bottom surface of the container 40 containing the cleaning solvent 4, and ultrasonic waves are applied to the perovskite solar cell module 1 by vibrating the ultrasonic vibrator 5.

[0042] After the prescribed processing time, such as Figure 3B As shown, multiple functional layers 3 are peeled off from the transparent substrate 2. Among the multiple functional layers 3, at least the perovskite photoelectric conversion layer 33 dissolves in the cleaning solvent 4. Furthermore, portions of the transparent electrode layer 31, electron transport layer 32, hole transport layer 34, back electrode layer 35, sealing layer 36, and backplate layer 37 peeled off from the transparent substrate 2 that do not dissolve in the cleaning solvent 4 may be recovered from the cleaning solvent 4 in solid form, as appropriate. The transparent substrate 2 may also be removed from the cleaning solvent 4 and recovered, as appropriate.

[0043] In the dissolution step (S1), even if the cleaning solvent 4 is water, multiple functional layers 3 can be completely peeled off from the transparent substrate 2 by applying ultrasound. In this case, the dissolution step (S1) is performed by water + ultrasound, followed by the precipitation step (S2) by adding sulfuric acid or the like. As the cleaning solvent 4, the reaction can be promoted by adding an acid (sulfuric acid, hydrochloric acid, nitric acid, acetic acid, etc.) to the water from the beginning. In this case, the dissolution step (S1) and the precipitation step (S2) can be performed simultaneously.

[0044] In the precipitation step (S2), lead dissolved in cleaning solvent 4 is precipitated as a sparingly soluble lead compound. When sulfuric acid is used as cleaning solvent 4, lead sulfate (PbSO4) precipitates; when hydrochloric acid is used, lead chloride (PbCl2) precipitates; when nitric acid is used, lead nitrate (Pb(NO3)2) precipitates; when acetic acid is used, lead acetate (Pb(CH3COO)2) precipitates; and when phosphoric acid is used, lead phosphate (Pb3(PO4)2) precipitates. Since it is desirable for the lead compound to have low solubility in cleaning solvent 4, sulfuric acid, phosphoric acid, and hydrochloric acid are preferred as cleaning solvent 4, with sulfuric acid being particularly preferred.

[0045] The total processing time for the dissolution step (S1) and the precipitation step (S2) is approximately 10 to 60 minutes. The preferred temperature range for the cleaning solvent 4 is approximately 20 to 100°C, and more preferably 40 to 80°C. The heating of the cleaning solvent 4 in the dissolution step (S1) can be performed, for example, by a heating device such as a jacketed heater disposed near the periphery of the container 40.

[0046] In the solid-liquid separation step (S3), the lead compound is separated from the washing solvent 4. Representative examples of methods for separating the lead compound from the washing solvent 4 include filtration, but are not limited to this; other methods such as centrifugation can also be used.

[0047] To improve the lead compound removal efficiency in the solid-liquid separation step (S3), it is preferable to cool the washing solvent 4 to below 10°C in the precipitation step (S2), if necessary. The cooling of the washing solvent 4 can be achieved using a heat exchanger such as a cooler. In this case, for example, as... Figure 3C As shown, while cooling and cleaning solvent 4, stirring is continued with mixer 6 to ensure that substances such as lead sulfate that should be separated precipitate evenly, thereby enabling the lead recovery efficiency to reach "close to the theoretical value".

[0048] In this embodiment, a dilute aqueous solution of sulfuric acid with a concentration of about 0.1 to 0.3 mol / L (more preferably 0.2 to 0.3 mol / L) is preferably used as the cleaning solvent 4. Therefore, lead sulfate, as a sparingly soluble lead compound, can preferably be recovered by filtration.

[0049] Following the solid-liquid separation step (S3), an adsorption step (S4) may be further included if necessary. In the adsorption step (S4), lead remaining in the washing solvent 4 after the solid-liquid separation step (S3) is adsorbed by a lead removal filter. The lead removal filter only needs to have the function of adsorbing lead ions; for example, ion exchange resin filters, activated carbon filters, silicate adsorption filters, etc., are preferred. If these filters are used, since they can be used as heavy metal removal filters, even if harmful metals other than lead (cadmium, zinc, etc.) are present, their concentration can be reduced to below 5 mg / L. Furthermore, known methods can be used for circulating liquid through the filter. Circulation through the filter can be either natural circulation at atmospheric pressure or pressurization or depressurization to shorten the processing time.

[0050] The above-described processing method for the perovskite solar cell module 1 can reduce the lead content of the cleaning solvent 4 after the solid-liquid separation step (S3) or after the adsorption step (S4) to below 0.05 mg / L. If the lead content of the cleaning solvent 4 is sufficiently low, the cleaning solvent 4 can be discharged, thus also addressing situations where a large amount of cleaning solvent 4 is generated.

[0051] The precipitate, mainly composed of lead compounds such as lead sulfate, recovered through the processing method of perovskite solar cell module 1 can also be reprocessed into reusable lead oxide through an incineration process. For example, by incinerating the recovered lead compounds to convert them into lead oxide (PbO), it can be used as a reusable resource in the manufacture of batteries, electronic components, chemical products, etc. In this case, since the amount of resources that can be effectively reused increases, the amount of waste generated from the discarded perovskite solar cell module 1 can be reduced.

[0052] <Other Implementation Methods>

[0053] • In the above embodiment, considering the ease of recycling the transparent substrate 2, an example of not crushing the perovskite solar cell module 1 is shown, but it is also possible to process it after crushing the perovskite solar cell module 1.

[0054]

Example

[0055] For the perovskite solar cell module 1, the residual lead concentration in the cleaning solvent 4 was measured after cleaning under various conditions. The perovskite solar cell module 1 used in the following experiments consisted of a functional layer 3, including a 180nm perovskite photoelectric conversion layer 33, formed on a 70mm × 70mm transparent substrate 2 (glass substrate). The perovskite photoelectric conversion layer 33 was CH3NH3PbI3 (lead methylamine iodide), with a density of 4 g / cm³. 3Since lead accounts for 59.5% of the total weight of the perovskite photoelectric conversion layer 33, it is assumed that each perovskite solar cell module 1 used in the experiment contains a calculated amount of 2.099 mg of lead.

[0056] The perovskite solar cell module 1 was placed into container 40 (a beaker was used in the experiment) without being crushed, and 100 mg of cleaning solvent 4 was added. Cleaning solvent 4 was a 0.2 mol / L dilute sulfuric acid aqueous solution. The experimental results obtained by changing the treatment time (equivalent to the total time of the dissolution step (S1) and precipitation step (S2)) to 10, 20, 30, and 60 minutes, and changing the temperature of cleaning solvent 4 to 20℃, 40℃, 60℃, 80℃, and 90℃ are shown in Table 1. The stirring speed was 200 rpm during the experiment.

[0057] Table 1

[0058]

[0059] The lead concentration in the solution was calculated by sampling the washing solvent 4 after removing sparingly soluble lead compounds (precipitates) through filter paper filtration, and measuring the values ​​using ICP mass spectrometry (using an Agilent Technologies 7900 ICP-MS). As shown in Table 1, in Experiment 8 (processing time 60 min, processing temperature 40 °C), Experiment 12 (processing time 60 min, processing temperature 60 °C), Experiment 15 (processing time 30 min, processing temperature 80 °C), and Experiment 16 (processing time 60 min, processing temperature 80 °C), the lead concentration in the solution reached below the environmental standard (less than 0.05 mg / L).

[0060] Next, in Experiment 8 (treatment time 60 minutes, treatment temperature 40℃), the correlation between the concentration of dilute sulfuric acid aqueous solution (0.1–0.3 mol / L) and the lead concentration in the solution was confirmed. The experimental results are shown in Table 2.

[0061] Table 2

[0062]

[0063] Regarding the effect of concentration, when the concentration of dilute sulfuric acid is 0.1 mol / L, the lead concentration in the solution increases compared to 0.2 mol / L. When the concentration of dilute sulfuric acid is 0.3 mol / L, the lead concentration in the solution decreases compared to 0.2 mol / L. From these results, it can be inferred that if the concentration of dilute sulfuric acid is between 0.2 and 0.3 mol / L, good results can be obtained regarding the lead concentration in the solution.

[0064] For the cleaning solvent 4 obtained in Experiment 4 above (dilute sulfuric acid concentration 0.2 mol / L, treatment time 60 minutes, treatment temperature 20℃) after removing the sparingly soluble lead compound (precipitate), the precipitation-promoting effect of cooling (filtration-promoting effect) was confirmed. To promote the precipitation of lead compounds, the temperature of the cleaning solvent 4 obtained in Experiment 4 was cooled to 5℃ and 10℃ respectively, and stirred for an additional 10 minutes. The experimental results at this time are shown in Table 3.

[0065] Table 3

[0066]

[0067] As shown in Table 3, it was confirmed that the lead concentration in the liquid was significantly reduced by cooling.

[0068] For the cleaning solvent 4 obtained after removing the sparingly soluble lead compounds (precipitate) in Experiment 5 above (dilute sulfuric acid concentration 0.2 mol / L, treatment time 10 minutes, treatment temperature 40℃), the lead adsorption effect was confirmed using three heavy metal removal filters. The experimental results at this time are shown in Table 4. The ion exchange resin filter was AmberLite™ IR120 H (Dow Chemical / DuPont), the activated carbon filter was AquaCarb® 1230C (Jacobs), and the silica adsorption filter was MPX-Press SilicaGel (Merck / Sigma-Aldrich).

[0069] Table 4

[0070]

[0071] The ion exchange resin filter (Experimental Example 5A) achieved the highest lead ion removal efficiency (99%), reducing the lead concentration in the solution to 0.02 mg / L. Its moderate processing speed also makes it suitable for large-scale treatment. In the activated carbon filter (Experimental Example 5B), the lead concentration was reduced to 0.03 mg / L. The removal efficiency was as high as 97%, but its performance may decline with long-term use. In the silicate adsorption filter (Experimental Example 5C), the lead concentration was reduced to 0.04 mg / L. The removal efficiency was slightly lower at 95%, but the fast processing speed makes it suitable for efficient, short-term treatment. These results suggest that the ion exchange resin filter offers the most effective and stable performance.

[0072] In addition, the lead sulfate (PbSO4) obtained in the above experiments was further processed into reusable lead oxide (PbO) through incineration (calcination). The three incineration conditions and their results are shown in Table 5. The sample was lead sulfate (PbSO4, weight 0.198 g). While changing the incineration conditions (incineration temperature, time, oxygen supply), the lead oxide formation rate, purity and energy consumption were measured.

[0073] Table 5

[0074]

[0075] In Experiment 21 (500℃, 40 minutes), the decomposition of lead sulfate was incomplete, with a lead oxide formation rate of 85%. The purity was 94%, achieving stable quality, but the low formation rate may be a challenge. Low energy consumption made it an effective low-cost option. In Experiment 22 (600℃, 30 minutes), the decomposition of lead sulfate was more complete, achieving a lead oxide formation rate of 96% and a purity of 97%. The balance between processing time, formation rate, purity, and energy consumption was good, considered optimal for industrial applications. In Experiment 23 (700℃, 20 minutes), a lead oxide formation rate of 98% and a purity of 99% were achieved. This is presumably due to the high oxygen supply and temperature, which allowed for the complete decomposition of the sulfuric acid components.

Claims

1. A method for processing a perovskite solar cell module, comprising a dissolution step, a precipitation step, and a solid-liquid separation step. The perovskite solar cell module includes a transparent substrate and multiple functional layers. The multiple functional layers include a perovskite photoelectric conversion layer. In the dissolution step, the perovskite solar cell module is immersed in a cleaning solvent and ultrasonic waves are applied to peel off the multiple functional layers from the transparent substrate, while simultaneously dissolving the perovskite photoelectric conversion layer in the cleaning solvent. In the precipitation step, lead dissolved in the cleaning solvent is precipitated as a sparingly soluble lead compound. In the solid-liquid separation step, the lead compound is separated from the cleaning solvent.

2. The method for processing a perovskite solar cell module according to claim 1, wherein, The cleaning solvent is a dilute sulfuric acid aqueous solution, and the sparingly soluble lead compound is lead sulfate.

3. The method for processing a perovskite solar cell module according to claim 1 or 2, wherein, In the dissolution step, the cleaning solvent is heated to 40–80°C.

4. The method for processing a perovskite solar cell module according to claim 3, wherein, In the precipitation step, the cleaning solvent is cooled to below 10°C.

5. The method for processing a perovskite solar cell module according to claim 1, wherein, It also includes an adsorption step, In the adsorption step, lead remaining in the cleaning solvent after the solid-liquid separation step is adsorbed by a lead removal filter.

6. The method for processing a perovskite solar cell module according to claim 1 or 5, wherein, The lead content of the cleaning solvent after the solid-liquid separation step or the lead content of the cleaning solvent after the adsorption step is less than 0.05 mg / L.

Images